G++ shared library

In Unix and Unix-like operating systems, a soname is a field of data in a shared object file . The soname is a string, which is used as a “logical name” describing the functionality of the object. Typically, that name is equal to the filename of the library, or to a prefix thereof, e.g. libc. so.

A shared object is an indivisible unit that is generated from one or more relocatable objects . Shared objects can be bound with dynamic executables to form a runable process. As their name implies, shared objects can be shared by more than one application.

LD_PRELOAD is an optional environmental variable containing one or more paths to shared libraries, or shared objects, that the loader will load before any other shared library including the C runtime library (libc.so) This is called preloading a library.